Rendering cooker flash steam recovery

The aim of this project was to design an improved system for recovering heat from rendering cooker condensate while it is still at high pressure. A common type of heat recovery is to use a flash steam recovery vessel to pre-heat the boiler feed water. This is usually done by installing a flash vessel between the cooker and the boiler feed tank and using a steam heat exchanger to condense the flash steam by pre-heating the boiler feed water.

This flash vessel is normally operated at less than 2 bar pressure so that it does not interfere with the operation of the cooker steam traps. The result is that the maximum temperature the boiler feed water can be heated to is typically less than 130°, limited by the pressure and therefore temperature of the flash steam. This lower temperature limits the amount of heat that can be recovered.

This research has provided proof of concept for an innovative heat recovery system that is cheaper and more efficient than conventional systems. This project recovers the heat from the cooker condensate while it is still at high pressure.